The present apparatus is directed to a fluid mud pump and, more particularly, to a mud pump to be utilized to intensity fluid pressure for use in drilling oil wells or in conditioning oil wells such as fracturing with extremely high pressure or abrasive fluids. Various mud pumps and pressure intensification pumps are already known to exist that employ various and sundry means to overcome the difficulties encountered in prolonged pumping of high volume, high pressure, and abrasive materials. The present invention is an apparatus which will provide improvement in mud pumping operations in such areas as less output pressure pulsation, less operating energy required for fluid pressure intensification, slower operating piston speeds and longer piston strokes thus resulting in extended life of valves, pistons, liners, and other operating parts, wider range of fluid flow and pressure controlability, greater simplicity of manufacture, adaptability, and operation, plus other less apparent improvements. Thus the context of the problem to be dealt with in the present invention is that of a high power, constant pressure, efficient, rugged, and controllable fluid output pump.